WORCESTER, Mass. — Gun control advocates, including one of the survivors of the Parkland, Florida, school shooting and the parents of one of the victims, are marching 50 miles (80 kilometers) across Massachusetts this week to the headquarters of gun manufacturer Smith & Wesson as part of a youth-led push for stricter gun laws.

About 40 students and supporters set off from downtown Worcester in central Massachusetts on Thursday morning holding signs denouncing gun violence and chanting slogans criticizing gun makers and the National Rifle Association. They're destined for Smith & Wesson's headquarters in Springfield, where they'll hold a large demonstration Sunday.

As he set off with marchers, David Hogg, a survivor of the February massacre at a Parkland high school who has since become a prominent gun control advocate, emphasized the importance of turning the energy of nationwide demonstrations into lasting political change.

"The kids of America have to stand up when our irresponsible politicians won't," he said. "We're here to elect morally just leaders that will protect us as Americans."

Manuel and Patricia Oliver, the parents of a Parkland shooting victim, also joined marchers and condemned Smith & Wesson for making the powerful rifle used to kill their 17-year-old son, Joaquin Oliver, and 16 others at Marjory Stoneman Douglas High School.

Manuel Oliver said the weapon isn't even allowed to be sold in the company's home state because of Massachusetts' strict gun laws. "That's an ironic situation," he said.

Spokespeople for the gun-maker didn't respond to requests for comment this week.

The company's headquarters was the site of a similar demonstration during March's nationwide protests against gun violence.

Smith & Wesson has become a target for gun control activists because the company's military-style rifles were used not only in the Parkland shooting but a number of other recent massacres, including the 2015 shooting at a California holiday party where 14 people died and the 2012 shooting at a Colorado movie theater where 12 died.

Thursday's marchers emphasized they're not looking to see the company, which was founded in 1852, move out of the state. They just want it to step up and do its part to make the country safer.

"I understand it's important to the city and its employs a lot of people," said Nate Lapointe, a 15-year-old high school junior from West Springfield. "But that doesn't give them a free pass on selling weapons that are used to commit mass murder. At some point, we have to hold them accountable."

Organizers for Thursday's "50 Miles More" march say they specifically want the gun-maker, which changed its parent company name to the American Outdoor Brands Corp. in 2016, to stop making weapons outlawed under Massachusetts' 2004 Assault Weapons Ban.

That law, which mirrors a federal ban that expired that year, prohibits the sale of certain military-style weapons, like Connecticut-based Colt's AR-15 and Italian gun-maker Beretta's AR70, as well as copycat versions of them.

March organizers also want Smith & Wesson to donate $5 million toward gun violence research because of the dearth of federally funded research on the issue thanks to restrictions imposed by Congress.

Supporting "commonsense" gun laws and respecting the constitutional right to bear arms aren't mutually exclusive, stressed Vikiana Petit-Homme, a senior at Boston Latin Academy in Boston and one of the event's lead organizers.

"You can still support the Second Amendment and still want to live and want stronger gun laws," she said. "It's not one or the other."

The name of Thursday's march is meant to echo the seminal civil rights era marches from Selma, Alabama, to the state capital in Montgomery that covered roughly 50 miles (80 kilometers).

The campaign started this spring with a march in Wisconsin from the state capitol in Madison to U.S. House Speaker Paul Ryan's hometown of Janesville.